For many years, multiwell laboratory plates have been manufactured in configurations ranging from 1 to 96 wells, and beyond. The wells of multiwell plates are typically used as reaction vessels for performing various tests, growing tissue cultures, screening drugs, or performing analytical and diagnostic functions. Industry standard multiwell plates are laid out with 96 wells in an 8.times.12 matrix (mutually perpendicular 8 and 12 well rows). Most multiwell plates also have stepped sidewalls to enable plates to be securely stacked one on another. In addition, the height, length and width of the 96 well plates are standardized. The standardization has resulted in the development of a large array of auxiliary equipment specifically developed for 96 well formats. The equipment includes devices that load and unload precise volumes of liquid in multiples of 8,12, or 96 wells at a time. In addition, equipment is available to transmit light through individual wells and to read colorimetric changes or chemiluminscence in individual wells. Some of the standardized equipment is designed to analyze and manipulate the data recorded.
Automation of analyses in the drug industry has fueled new methods of drug discovery: high throughput screening and combinatorial chemistry. By using these techniques, pools of thousands of compounds having slight chemical variations are screened en masse. Only a small fraction of drug candidates show promise, but by testing thousands or even millions of compounds, the likelihood of stumbling on a compound with promising biological activity is increased.
In order to test these thousands of compounds, drug manufacturers have relied on the industry standard multiwell plate, usually having a format of 96 wells. In order to begin the automated drug screening process, a storage magazine having a plurality of slots (typically 20 or more), each sized to receive a single multiwell plate, is loaded by hand. The plates are thereafter taken by robotic means to various stations where sample manipulations are performed.
The slots in the magazine are spaced such that individual plates may be taken from the slots by means of robotic handling equipment. Currently, the slots in the storage magazine are loaded by manually taking one plate at a time from the manufacturer's shipping carton and loading into the individual slots. Considering the speed at which plates are tested, this process is continuous and time consuming.